The invention relates to a device for supplying material to a container.
The invention is particularly suitable for loading or filling containers and devices with material, the material being stored, processed or worked therein under an overpressure or underpressure.
A preferred field of application are milling plants, where raw material is supplied to vertical mills with air flow conveying, e.g. air-swept roller mills, with the aid of conveying devices and a feed device for milling purposes.
For charging a vertical mill with raw material to be crushed, e.g. predried raw lignite or cement clinker and fluxes, it is known to use a two or three-flap lock or a bucket wheel lock, which ensures the necessary sealing of an air-swept mill operated under an overpressure or underpressure.
However, the disadvantage is that these material locks involve high costs, which considerably increase the overall costs of a milling plant. This is in particular due to the overall height of the flap and bucket wheel locks and the arrangement thereof roughly level with a classifier cover caused by the material being discharged vertically. Besides the costs resulting from the building height, costs are also involved for the mechanical and electrotechnical equipment and for assembly and this has a negative effect on the total costs of a milling plant.
FIG. 1 shows in a partial view a milling plant 2 in the vicinity of an air-swept roller mill as a vertical mill 6 with air flow conveying. A bucket wheel lock 45 is used as the feed mechanism for the milling material to be crushed and which is supplied from a silo or hopper 37 to a conveyor 43. The bucket wheel lock 45 is positioned above a classifier cover 46 of the vertical mill 6. The not shown milling material passes via a feed chute 47 into the milling area 12 of the vertical mill 6. FIG. 1 illustrates the considerable building height, the necessary structural plant parts and the length of the conveyor 43, which raise the total cost of the milling plant.
Austrian patent 400 684 discloses a device for supplying raw coal to a mill which is under pressure. In order to limit to a minimum the parts which have to be designed in pressure shock-resistant manner, following a silo the supply device has a first conveying line, followed by a feed bunker, a second conveying line, an intermediate bunker and a third conveying line. The third conveying line is in the form of a trough chain conveyor, which serves as a proportioning member and is fully located in a pressure shock-resistant casing. By means of the supply shaft issuing centrally into the classifier cover of the mill, the raw coal passes from the third conveying line into the mill. As a result of the superimposed bunkers and the horizontally positioned, three conveying lines, the overall supply device has a relatively large overall height and requires corresponding capital, assembly and energy costs.
DE 88 05 885 U1 discloses a mill for crushing moist milling material with a feed chute for supplying said material. A conveyor belt projects into the sloping feed chute, which extends into an introduction opening in the mill casing cover. In order to protect the conveyor belt parts located in the feed chute against the rising hot gases from the mill in the case of a power failure, a stack is provided which is connected to the feed chute. At the connection point of the stack in the feed chute is provided a shutoff valve as a movable part of a gas deflector, which in normal operation shuts off the stack, whereas in the case of a power failure it opens the stack and shuts off the feed chute. The additional components located in the cover-side supply device increase the overall height, as well as the capital expenditure and control technology expenditure of the milling plant.
An elevator conveyor for bulk materials with two continuous conveyor belts, which engage on one another on their longitudinal edges and whereof at least one passes in a vertical area within an air box is known from DE 27 26 038 C2. Pretensioning means and sealing strips fixed to the air box are provided for the necessary marginal sealing of the conveyor belts.
A double band or strap belt conveyor is known from DE 34 32 553 A1. In order to be able to convey sticky, slurry-like and highly free-flowing bulk materials reliably and without any demixing risk, the cover belt strap has longitudinal and transverse reinforcements between which are formed indentations for receiving the material to be conveyed. The indentations or conveying spaces are sealed to the other side by the second, flat strap of the conveyor belt. Through longitudinal guides comprise U-shaped steel section portions and ensure the necessary seals for the conveying spaces.